Activity 1 Research models basic genetics and PCR What are model organisms models that involve genetics genetics 101 PCR genotyping This week s assignment will give a basic overview about how research models are chosen Choosing the best research model for a particular project requires a lot of background research and is one of the most important things in a project Instructions From Part1 to Part 4 if you consult online resources put the link at the end of each answer Part 1 Model Organisms What are model organisms 1 what is the purpose of using model organisms in biological research Use for experiment identical with each other A model organism is a species used by researchers to study specific biological processes They have similar genetic characteristics to humans and are typically chosen for their easy maintenance and reproduction in a laboratory setting short generation cycles or the capacity to generate mutants to study certain traits or diseases Model organisms provide valuable insights into biological systems at the cell tissue organ and system level https www leica microsystems com applications life science model organisms in research 2 list common examples of model organisms Mice rats zebrafish rabbits 3 what are some challenges of using model organisms for studying human diseases Model organisms are cultured in the lab and not studied in their natural environment which could cause deviations from their normal behavior or biological processes Not the same species more similar to humans are more expensive What are a few common model organisms used for studying human pregnancy placenta Ex mouse sheep rat horse cow rabbit dog cat Guinea pig mouse sheep separation What are the different types of placentas based on classifications based on circulatory There are four main placenta types recognized by gross morphology and whether the maternal fetal exchange area is found over all the available surface of the chorionic sac or whether it is restricted Diffuse horses pigs Multicotyledonary ruminants Zonary carnivores Discoid Bidiscoid primates rodents rabbits Based on the answers above what are the benefits of using a mice model in the project you worked on Most closely resembles the human placenta rats are more similar to humans but more expensive Part 2 Transgenic Mouse models What is a transgenic mouse model Mice that have had DNA from another source put into their DNA Modify the gene https www cancer gov publications dictionaries cancer terms def transgenic mice What are some of the benefits and drawbacks of using transgenic mice models Transgenic mice models can allow the modeling of the development of human diseases in a controlled environment target specific genes to study and allow researchers to replicate specific characteristics symptoms or pathology of disease Some human diseases cannot be fully modeled or develop differently in the mouse This can be a significant drawback in understanding the disease and evaluating potential disease treatments Even if most of the disease model parameters check out and a treatment works in mice it might not always work in humans the same way https www genetargeting com transgenic transgenic mouse model Part3 Genetics 101 Briefly define the following Alleles varieties of a gene Homozygous having two identical versions of the same gene Heterozygous having inherited different versions alleles of a genomic marker Transgenic mouse Mice that have had DNA from another source put into their from each biological parent DNA Knockout mouse a laboratory mouse in which researchers have inactivated or knocked out an existing gene by replacing it or disrupting it with an artificial piece of DNA Remove both strands Knockdown mouse an animal model in which the gene expression of a certain specific gene is only reduced by about 70 Remove 1 strand Knockin mouse animal model in which a gene sequence of interest is altered by one for one substitution with a transgene or by adding gene sequences that are not found within the locus Conditional knockout is a technique that eliminates gene expression in a specific organ tissue or cell at a specific time What is a cre lox breeding system Describe the Cre lox system using the information 1 The Cre lox system is one of the most popular genetic modification system used in mice below In this image Alb represents albumin which is specifically expressed in the liver We normally name the mice with the loxP as X fl X refers to the interested gene name If the mice carry one pair of loxP if will be named as X fl if it carries two pairs of loxP it will be named as X fl fl 2 Cre a single Cre recombinase In genetics floxing refers to the sandwiching of a DNA sequence which is then said to be floxed between two lox P sites What is a conditional cre lox knockout What is global knownout Part 4 Polymerase chain reaction What is a polymerase chain reaction A laboratory technique for rapidly producing amplifying millions to billions of copies of a specific segment of DNA which can then be studied in greater detail What are the different steps of PCR cycling Denaturing when the double stranded template DNA is heated to separate it into two single strands Annealing when the temperature is lowered to enable the DNA primers to attach to the template DNA Only once the primer has bound can the polymerase enzyme attach and start making the new complementary strand of DNA from the loose DNA bases Extending when the temperature is raised and the new strand of DNA is made by the polymerase enzyme Put the following in order gel electrophoresis with EtBr gel PCR boil collect tail samples UV exposure of bands Activity 2 1 According to the Mendelian inheritance answer the following genetic questions a What s the possibility to get aaBb from AaBbXAABB 2 Practice genetic problems Briefly answer the following a If ppar gamma female is bred with a ppar gamma male what are the possible genotypes for the offspring and at what ratios If ppar gamma female is bred with a ppar gamma male what are the possible genotypes for the offspring and at what ratios If ppar gamma female is bred with a ppar gamma male what are the possible genotypes for the offspring and at what ratios 3 I want to generate a PPARg fl fl Alb Cre mice using a male PPARg fl and a female Alb Cre mice how shall I design my breeding scheme How many generations will it take